LEAFY and WAPO1 jointly regulate spikelet number per spike and floret development in wheat

Area of Science:

• Plant genetics
• Molecular biology
• Agronomy

Background:

• Spikelet number per spike (SNS) is a key determinant of wheat yield.
• The transition from inflorescence meristem to terminal spikelet (IM→TS) governs SNS.
• Understanding the genetic regulation of SNS is vital for crop engineering.

Purpose of the Study:

• To investigate the roles of LEAFY (LFY) and WHEAT ORTHOLOG OF APO1 (WAPO1) in regulating wheat SNS.
• To elucidate the genetic interactions governing the IM→TS transition and floret development.
• To identify key genetic networks for enhancing wheat yield.

Main Methods:

• Genetic analysis of loss-of-function mutations in LFY and WAPO1.
• Investigating genetic interactions between LFY, WAPO1, VRN1, and FUL2.
• Single-molecule fluorescence in situ hybridization (smFISH) to analyze gene expression patterns.

Main Results:

• LFY and WAPO1 physically and genetically interact to regulate SNS and floret development.
• Mutations in LFY or WAPO1 reduce SNS by decreasing spikelet meristem formation rate.
• LFY interacts antagonistically with SQUAMOSA MADS-box genes (VRN1, FUL2) in SNS regulation.

Conclusions:

• LFY and WAPO1 are crucial regulators of wheat spikelet development and number.
• The interplay between LFY, WAPO1, and MADS-box genes shapes SNS.
• Targeting these genetic pathways offers potential for improving wheat yield.